Python

reading column data

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Join Date: Sep 2007

Posts: 6

Reputation: random7 is an unknown quantity at this point

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random7

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reading column data

Apr 17th, 2008

Hi, everyone

I have a question about reading column data from file.

helium.dat
He 1.31
He 1.32
He 1.39
He 1.41
He 1.38
He 1.39
He 1.21
He 1.45
He 2.31

I want to print just the 2nd column data(number) from helium.dat like below
1.31
1.32
1.39
1.41
1.38
1.39
1.21
1.45
2.31

 Help with Code Tags 
 Python Syntax (Toggle Plain Text) 
from numpy import*
f = loadtxt("helium.dat")                                
data = f[:, 1]
 
for i in range(8):
  print data[i]
from numpy import*
f = loadtxt("helium.dat")                                
data = f[:, 1]

for i in range(8):
  print data[i]

I used this code, but that's wrong because loadtxt supports only numbers.
Please help me

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Join Date: Sep 2007

Posts: 6

Reputation: random7 is an unknown quantity at this point

Solved Threads: 0

random7

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Newbie Poster

Re: reading column data

Apr 18th, 2008

First time, I think that i can't do it by myself.
But luckly, I got it.

 Help with Code Tags 
 Python Syntax (Toggle Plain Text) 
from numpy import*
 
x0 = []
for line in file('helium.dat'):
  line = line.lstrip('He')
  line_list = [float(x) for x in line.split()]
  x0.append(line_list)
 
for i in range(len(x0)):
  print array(x0[i]).item()
from numpy import*

x0 = []
for line in file('helium.dat'):
  line = line.lstrip('He')
  line_list = [float(x) for x in line.split()]
  x0.append(line_list)

for i in range(len(x0)):
  print array(x0[i]).item()

result:
1.31
1.32
1.39
1.41
1.38
1.39
1.21
1.45
2.31

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Join Date: Sep 2007

Posts: 6

Reputation: random7 is an unknown quantity at this point

Solved Threads: 0

random7

Offline

Newbie Poster

Re: reading column data

Apr 18th, 2008

I got more simple code, which gives same result.

 Help with Code Tags 
 Python Syntax (Toggle Plain Text) 
from numpy import*
 
x0 = []
for line in file('helium.dat'):
   line = line.split()
   x = line[1]
   x0.append(x)
 
for i in range(len(x0)):
   print x0[i]
from numpy import*
 
x0 = []
for line in file('helium.dat'):
   line = line.split()
   x = line[1]
   x0.append(x)

for i in range(len(x0)):
   print x0[i]

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Join Date: Sep 2008

Posts: 2

Reputation: hardik.38 is an unknown quantity at this point

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hardik.38

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Re: reading column data..no need of additional code u people write

Sep 2nd, 2008

def main():
x0=[]
for line in file('C:\h1.txt'):
line = line.split()
x = line[1]
print x

Hi...Guys..i just join community last night...and I think u have done a great job...but i thnk the code u write is bit long..we can make it short bye just like i have done above..

thanx..hardik here...